Techniques and apparatuses for spatial diversity in a coordinated multipoint network

ABSTRACT

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive a plurality of communications from a corresponding plurality of transmission/reception points (TRPs) included in a coordinated multipoint network. At least two communications, of the plurality of communications, may have different redundancy versions from a common codebook, and may be received in a same transmission time interval (TTI). The UE may decode the plurality of communications using joint decoding. Numerous other aspects are provided.

CROSS-REFERENCE TO RELATED APPLICATIONS UNDER 35 U.S.C. § 119

This application claims priority to U.S. Provisional Patent ApplicationNo. 62/620,836, filed on Jan. 23, 2018, entitled “TECHNIQUES ANDAPPARATUSES FOR SPATIAL DIVERSITY IN A COORDINATED MULTIPOINT NETWORK,”which is hereby expressly incorporated by reference herein.

FIELD OF THE DISCLOSURE

Aspects of the present disclosure generally relate to wirelesscommunication, and more particularly to techniques and apparatuses forspatial diversity in a coordinated multipoint network.

BACKGROUND

Wireless communication systems are widely deployed to provide varioustelecommunication services such as telephony, video, data, messaging,and broadcasts. Typical wireless communication systems may employmultiple-access technologies capable of supporting communication withmultiple users by sharing available system resources (e.g., bandwidth,transmit power, and/or the like). Examples of such multiple-accesstechnologies include code division multiple access (CDMA) systems, timedivision multiple access (TDMA) systems, frequency-division multipleaccess (FDMA) systems, orthogonal frequency-division multiple access(OFDMA) systems, single-carrier frequency-division multiple access(SC-FDMA) systems, time division synchronous code division multipleaccess (TD-SCDMA) systems, and Long Term Evolution (LTE).LTE/LTE-Advanced is a set of enhancements to the Universal MobileTelecommunications System (UMTS) mobile standard promulgated by theThird Generation Partnership Project (3GPP).

A wireless communication network may include a number of base stations(BSs) that can support communication for a number of user equipment(UEs). A user equipment (UE) may communicate with a base station (BS)via the downlink and uplink. The downlink (or forward link) refers tothe communication link from the BS to the UE, and the uplink (or reverselink) refers to the communication link from the UE to the BS. As will bedescribed in more detail herein, a BS may be referred to as a Node B, agNB, an access point (AP), a radio head, a transmit receive point (TRP),a new radio (NR) BS, a 5G Node B, and/or the like.

The above multiple access technologies have been adopted in varioustelecommunication standards to provide a common protocol that enablesdifferent user equipment to communicate on a municipal, national,regional, and even global level. New radio (NR), which may also bereferred to as 5G, is a set of enhancements to the LTE mobile standardpromulgated by the Third Generation Partnership Project (3GPP). NR isdesigned to better support mobile broadband Internet access by improvingspectral efficiency, lowering costs, improving services, making use ofnew spectrum, and better integrating with other open standards usingorthogonal frequency division multiplexing (OFDM) with a cyclic prefix(CP) (CP-OFDM) on the downlink (DL), using CP-OFDM and/or SC-FDM (e.g.,also known as discrete Fourier transform spread OFDM (DFT-s-OFDM)) onthe uplink (UL), as well as supporting beamforming, multiple-inputmultiple-output (MIMO) antenna technology, and carrier aggregation.However, as the demand for mobile broadband access continues toincrease, there exists a need for further improvements in LTE and NRtechnologies. Preferably, these improvements should be applicable toother multiple access technologies and the telecommunication standardsthat employ these technologies.

SUMMARY

In some aspects, a method of wireless communication, performed by a userequipment (UE), may include receiving a plurality of communications froma corresponding plurality of transmission/reception points (TRPs)included in a coordinated multipoint network, wherein at least twocommunications, of the plurality of communications, have differentredundancy versions from a common codebook and are received in a sametransmission time interval (TTI); and decoding the plurality ofcommunications using joint decoding.

In some aspects, a method of wireless communication, performed by afirst transmission/reception point (TRP) included in a coordinatedmultipoint network, may include identifying a first redundancy versionfor a first communication to be transmitted to a user equipment (UE) ina transmission time interval (TTI); and transmitting the firstcommunication, having the first redundancy version, in the TTI, whereinthe first redundancy version is different from a second redundancyversion of a second communication to be transmitted by a second TRP inthe TTI, wherein the second TRP is included in the coordinatedmultipoint network.

In some aspects, a user equipment (UE) for wireless communication mayinclude memory and one or more processors operatively coupled to thememory. The memory and the one or more processors may be configured toreceive a plurality of communications from a corresponding plurality oftransmission/reception points (TRPs) included in a coordinatedmultipoint network, wherein at least two communications, of theplurality of communications, have different redundancy versions from acommon codebook and are received in a same transmission time interval(TTI); and decode the plurality of communications using joint decoding.

In some aspects, a first transmission/reception point (TRP), included ina coordinated multipoint network, for wireless communication may includememory and one or more processors operatively coupled to the memory. Thememory and the one or more processors may be configured to identify afirst redundancy version for a first communication to be transmitted toa user equipment (UE) in a transmission time interval (TTI); andtransmit the first communication, having the first redundancy version,in the TTI, wherein the first redundancy version is different from asecond redundancy version of a second communication to be transmitted bya second TRP in the TTI, wherein the second TRP is included in thecoordinated multipoint network.

In some aspects, a non-transitory computer-readable medium may store oneor more instructions for wireless communication. The one or moreinstructions, when executed by one or more processors of a userequipment (UE), may cause the one or more processors to receive aplurality of communications from a corresponding plurality oftransmission/reception points (TRPs) included in a coordinatedmultipoint network, wherein at least two communications, of theplurality of communications, have different redundancy versions from acommon codebook and are received in a same transmission time interval(TTI); and decode the plurality of communications using joint decoding.

In some aspects, a non-transitory computer-readable medium may store oneor more instructions for wireless communication. The one or moreinstructions, when executed by one or more processors of a firsttransmission/reception point (TRP) included in a coordinated multipointnetwork, may cause the one or more processors to identify a firstredundancy version for a first communication to be transmitted to a userequipment (UE) in a transmission time interval (TTI); and transmit thefirst communication, having the first redundancy version, in the TTI,wherein the first redundancy version is different from a secondredundancy version of a second communication to be transmitted by asecond TRP in the TTI, wherein the second TRP is included in thecoordinated multipoint network.

In some aspects, an apparatus for wireless communication may includemeans for receiving a plurality of communications from a correspondingplurality of transmission/reception points (TRPs) included in acoordinated multipoint network, wherein at least two communications, ofthe plurality of communications, have different redundancy versions froma common codebook and are received in a same transmission time interval(TTI); and means for decoding the plurality of communications usingjoint decoding.

In some aspects, a first apparatus, included in a coordinated multipointnetwork, for wireless communication may include means for identifying afirst redundancy version for a first communication to be transmitted toa user equipment (UE) in a transmission time interval (TTI); and meansfor transmitting the first communication, having the first redundancyversion, in the TTI, wherein the first redundancy version is differentfrom a second redundancy version of a second communication to betransmitted by a second apparatus in the TTI, wherein the secondapparatus is included in the coordinated multipoint network.

Aspects generally include a method, apparatus, system, computer programproduct, non-transitory computer-readable medium, user equipment, basestation, wireless communication device, transmission/reception point,controller, and processing system as substantially described herein withreference to and as illustrated by the accompanying drawings andspecification.

The foregoing has outlined rather broadly the features and technicaladvantages of examples according to the disclosure in order that thedetailed description that follows may be better understood. Additionalfeatures and advantages will be described hereinafter. The conceptionand specific examples disclosed may be readily utilized as a basis formodifying or designing other structures for carrying out the samepurposes of the present disclosure. Such equivalent constructions do notdepart from the scope of the appended claims. Characteristics of theconcepts disclosed herein, both their organization and method ofoperation, together with associated advantages will be better understoodfrom the following description when considered in connection with theaccompanying figures. Each of the figures is provided for the purpose ofillustration and description, and not as a definition of the limits ofthe claims.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above-recited features of the presentdisclosure can be understood in detail, a more particular description,briefly summarized above, may be had by reference to aspects, some ofwhich are illustrated in the appended drawings. It is to be noted,however, that the appended drawings illustrate only certain typicalaspects of this disclosure and are therefore not to be consideredlimiting of its scope, for the description may admit to other equallyeffective aspects. The same reference numbers in different drawings mayidentify the same or similar elements.

FIG. 1 is a block diagram conceptually illustrating an example of awireless communication network, in accordance with various aspects ofthe present disclosure.

FIG. 2 is a block diagram conceptually illustrating an example of a basestation in communication with a user equipment (UE) in a wirelesscommunication network, in accordance with various aspects of the presentdisclosure.

FIG. 3A is a block diagram conceptually illustrating an example of aframe structure in a wireless communication network, in accordance withvarious aspects of the present disclosure.

FIG. 3B is a block diagram conceptually illustrating an examplesynchronization communication hierarchy in a wireless communicationnetwork, in accordance with various aspects of the present disclosure.

FIG. 4 is a block diagram conceptually illustrating an example subframeformat with a normal cyclic prefix, in accordance with various aspectsof the present disclosure.

FIG. 5 illustrates an example logical architecture of a distributedradio access network (RAN), in accordance with various aspects of thepresent disclosure.

FIG. 6 illustrates an example physical architecture of a distributedRAN, in accordance with various aspects of the present disclosure.

FIGS. 7 and 8 are diagrams illustrating examples of spatial diversity ina coordinated multipoint network, in accordance with various aspects ofthe present disclosure.

FIGS. 9 and 10 are diagrams illustrating example processes for spatialdiversity in a coordinated multipoint network, in accordance withvarious aspects of the present disclosure.

DETAILED DESCRIPTION

Various aspects of the disclosure are described more fully hereinafterwith reference to the accompanying drawings. This disclosure may,however, be embodied in many different forms and should not be construedas limited to any specific structure or function presented throughoutthis disclosure. Rather, these aspects are provided so that thisdisclosure will be thorough and complete, and will fully convey thescope of the disclosure to those skilled in the art. Based on theteachings herein one skilled in the art should appreciate that the scopeof the disclosure is intended to cover any aspect of the disclosuredisclosed herein, whether implemented independently of or combined withany other aspect of the disclosure. For example, an apparatus may beimplemented or a method may be practiced using any number of the aspectsset forth herein. In addition, the scope of the disclosure is intendedto cover such an apparatus or method which is practiced using otherstructure, functionality, or structure and functionality in addition toor other than the various aspects of the disclosure set forth herein. Itshould be understood that any aspect of the disclosure disclosed hereinmay be embodied by one or more elements of a claim.

Several aspects of telecommunication systems will now be presented withreference to various apparatuses and techniques. These apparatuses andtechniques will be described in the following detailed description andillustrated in the accompanying drawings by various blocks, modules,components, circuits, steps, processes, algorithms, and/or the like(collectively referred to as “elements”). These elements may beimplemented using hardware, software, or combinations thereof. Whethersuch elements are implemented as hardware or software depends upon theparticular application and design constraints imposed on the overallsystem.

It is noted that while aspects may be described herein using terminologycommonly associated with 3G and/or 4G wireless technologies, aspects ofthe present disclosure can be applied in other generation-basedcommunication systems, such as 5G and later, including NR technologies.

FIG. 1 is a diagram illustrating a network 100 in which aspects of thepresent disclosure may be practiced. The network 100 may be an LTEnetwork or some other wireless network, such as a 5G or NR network.Wireless network 100 may include a number of BSs 110 (shown as BS 110 a,BS 110 b, BS 110 c, and BS 110 d) and other network entities. A BS is anentity that communicates with user equipment (UEs) and may also bereferred to as a base station, a NR BS, a Node B, a gNB, a 5G node B(NB), an access point, a transmit receive point (TRP), and/or the like.Each BS may provide communication coverage for a particular geographicarea. In 3GPP, the term “cell” can refer to a coverage area of a BSand/or a BS subsystem serving this coverage area, depending on thecontext in which the term is used.

A BS may provide communication coverage for a macro cell, a pico cell, afemto cell, and/or another type of cell. A macro cell may cover arelatively large geographic area (e.g., several kilometers in radius)and may allow unrestricted access by UEs with service subscription. Apico cell may cover a relatively small geographic area and may allowunrestricted access by UEs with service subscription. A femto cell maycover a relatively small geographic area (e.g., a home) and may allowrestricted access by UEs having association with the femto cell (e.g.,UEs in a closed subscriber group (CSG)). ABS for a macro cell may bereferred to as a macro BS. ABS for a pico cell may be referred to as apico BS. A BS for a femto cell may be referred to as a femto BS or ahome BS. In the example shown in FIG. 1, a BS 110 a may be a macro BSfor a macro cell 102 a, a BS 110 b may be a pico BS for a pico cell 102b, and a BS 110 c may be a femto BS for a femto cell 102 c. A BS maysupport one or multiple (e.g., three) cells. The terms “eNB”, “basestation”, “NR BS”, “gNB”, “TRP”, “AP”, “node B”, “5G NB”, and “cell” maybe used interchangeably herein.

In some aspects, a cell may not necessarily be stationary, and thegeographic area of the cell may move according to the location of amobile BS. In some aspects, the BSs may be interconnected to one anotherand/or to one or more other BSs or network nodes (not shown) in theaccess network 100 through various types of backhaul interfaces such asa direct physical connection, a virtual network, and/or the like usingany suitable transport network.

Wireless network 100 may also include relay stations. A relay station isan entity that can receive a transmission of data from an upstreamstation (e.g., a BS or a UE) and send a transmission of the data to adownstream station (e.g., a UE or a BS). A relay station may also be aUE that can relay transmissions for other UEs. In the example shown inFIG. 1, a relay station 110 d may communicate with macro BS 110 a and aUE 120 d in order to facilitate communication between BS 110 a and UE120 d. A relay station may also be referred to as a relay BS, a relaybase station, a relay, and/or the like.

Wireless network 100 may be a heterogeneous network that includes BSs ofdifferent types, e.g., macro BSs, pico BSs, femto BSs, relay BSs, and/orthe like. These different types of BSs may have different transmit powerlevels, different coverage areas, and different impact on interferencein wireless network 100. For example, macro BSs may have a high transmitpower level (e.g., 5 to 40 Watts) whereas pico BSs, femto BSs, and relayBSs may have lower transmit power levels (e.g., 0.1 to 2 Watts).

A network controller 130 may couple to a set of BSs and may providecoordination and control for these BSs. Network controller 130 maycommunicate with the BSs via a backhaul. The BSs may also communicatewith one another, e.g., directly or indirectly via a wireless orwireline backhaul.

UEs 120 (e.g., 120 a, 120 b, 120 c) may be dispersed throughout wirelessnetwork 100, and each UE may be stationary or mobile. A UE may also bereferred to as an access terminal, a terminal, a mobile station, asubscriber unit, a station, and/or the like. A UE may be a cellularphone (e.g., a smart phone), a personal digital assistant (PDA), awireless modem, a wireless communication device, a handheld device, alaptop computer, a cordless phone, a wireless local loop (WLL) station,a tablet, a camera, a gaming device, a netbook, a smartbook, anultrabook, medical device or equipment, biometric sensors/devices,wearable devices (smart watches, smart clothing, smart glasses, smartwrist bands, smart jewelry (e.g., smart ring, smart bracelet)), anentertainment device (e.g., a music or video device, or a satelliteradio), a vehicular component or sensor, smart meters/sensors,industrial manufacturing equipment, a global positioning system device,or any other suitable device that is configured to communicate via awireless or wired medium.

Some UEs may be considered machine-type communication (MTC) or evolvedor enhanced machine-type communication (eMTC) UEs. MTC and eMTC UEsinclude, for example, robots, drones, remote devices, such as sensors,actuators, programmable logic controllers (PLCs), meters, monitors,location tags, and/or the like, that may communicate with a basestation, another device (e.g., remote device), or some other entity. Awireless node may provide, for example, connectivity for or to a network(e.g., a wide area network such as Internet or a cellular network) via awired or wireless communication link. Some UEs may be consideredInternet-of-Things (IoT) devices, and/or may be implemented as may beimplemented as NB-IoT (narrowband internet of things) devices. Some UEsmay be considered a Customer Premises Equipment (CPE). UE 120 may beincluded inside a housing that houses components of UE 120, such asprocessor components, memory components, and/or the like.

In general, any number of wireless networks may be deployed in a givengeographic area. Each wireless network may support a particular RAT andmay operate on one or more frequencies. A RAT may also be referred to asa radio technology, an air interface, and/or the like. A frequency mayalso be referred to as a carrier, a frequency channel, and/or the like.Each frequency may support a single RAT in a given geographic area inorder to avoid interference between wireless networks of different RATs.In some cases, NR or 5G RAT networks may be deployed.

In some aspects, two or more UEs 120 (e.g., shown as UE 120 a and UE 120e) may communicate directly using one or more sidelink channels (e.g.,without using a base station 110 as an intermediary to communicate withone another). For example, the UEs 120 may communicate usingpeer-to-peer (P2P) communications, device-to-device (D2D)communications, a vehicle-to-everything (V2X) protocol (e.g., which mayinclude a vehicle-to-vehicle (V2V) protocol, a vehicle-to-infrastructure(V2I) protocol, and/or the like), a mesh network, and/or the like. Inthis case, the UE 120 may perform scheduling operations, resourceselection operations, and/or other operations described elsewhere hereinas being performed by the base station 110.

As indicated above, FIG. 1 is provided merely as an example. Otherexamples are possible and may differ from what was described with regardto FIG. 1.

FIG. 2 shows a block diagram of a design 200 of base station 110 and UE120, which may be one of the base stations and one of the UEs in FIG. 1.Base station 110 may be equipped with T antennas 234 a through 234 t,and UE 120 may be equipped with R antennas 252 a through 252 r, where ingeneral T≥1 and R≥1.

At base station 110, a transmit processor 220 may receive data from adata source 212 for one or more UEs, select one or more modulation andcoding schemes (MCS) for each UE based at least in part on channelquality indicators (CQIs) received from the UE, process (e.g., encodeand modulate) the data for each UE based at least in part on the MCS(s)selected for the UE, and provide data symbols for all UEs. Transmitprocessor 220 may also process system information (e.g., for semi-staticresource partitioning information (SRPI) and/or the like) and controlinformation (e.g., CQI requests, grants, upper layer signaling, and/orthe like) and provide overhead symbols and control symbols. Transmitprocessor 220 may also generate reference symbols for reference signals(e.g., the cell-specific reference signal (CRS)) and synchronizationsignals (e.g., the primary synchronization signal (PSS) and secondarysynchronization signal (SSS)). A transmit (TX) multiple-inputmultiple-output (MIMO) processor 230 may perform spatial processing(e.g., precoding) on the data symbols, the control symbols, the overheadsymbols, and/or the reference symbols, if applicable, and may provide Toutput symbol streams to T modulators (MODs) 232 a through 232 t. Eachmodulator 232 may process a respective output symbol stream (e.g., forOFDM and/or the like) to obtain an output sample stream. Each modulator232 may further process (e.g., convert to analog, amplify, filter, andupconvert) the output sample stream to obtain a downlink signal. Tdownlink signals from modulators 232 a through 232 t may be transmittedvia T antennas 234 a through 234 t,respectively. According to variousaspects described in more detail below, the synchronization signals canbe generated with location encoding to convey additional information.

At UE 120, antennas 252 a through 252 r may receive the downlink signalsfrom base station 110 and/or other base stations and may providereceived signals to demodulators (DEMODs) 254 a through 254 r,respectively. Each demodulator 254 may condition (e.g., filter, amplify,downconvert, and digitize) a received signal to obtain input samples.Each demodulator 254 may further process the input samples (e.g., forOFDM and/or the like) to obtain received symbols. A MIMO detector 256may obtain received symbols from all R demodulators 254 a through 254 r,perform MIMO detection on the received symbols if applicable, andprovide detected symbols. A receive processor 258 may process (e.g.,demodulate and decode) the detected symbols, provide decoded data for UE120 to a data sink 260, and provide decoded control information andsystem information to a controller/processor 280. A channel processormay determine reference signal received power (RSRP), received signalstrength indicator (RSSI), reference signal received quality (RSRQ),channel quality indicator (CQI), and/or the like.

On the uplink, at UE 120, a transmit processor 264 may receive andprocess data from a data source 262 and control information (e.g., forreports comprising RSRP, RSSI, RSRQ, CQI, and/or the like) fromcontroller/processor 280. Transmit processor 264 may also generatereference symbols for one or more reference signals. The symbols fromtransmit processor 264 may be precoded by a TX MIMO processor 266 ifapplicable, further processed by modulators 254 a through 254 r (e.g.,for DFT-s-OFDM, CP-OFDM, and/or the like), and transmitted to basestation 110. At base station 110, the uplink signals from UE 120 andother UEs may be received by antennas 234, processed by demodulators232, detected by a MIMO detector 236 if applicable, and furtherprocessed by a receive processor 238 to obtain decoded data and controlinformation sent by UE 120. Receive processor 238 may provide thedecoded data to a data sink 239 and the decoded control information tocontroller/processor 240. Base station 110 may include communicationunit 244 and communicate to network controller 130 via communicationunit 244. Network controller 130 may include communication unit 294,controller/processor 290, and memory 292.

In some aspects, one or more components of UE 120 may be included in ahousing. Controller/processor 240 of base station 110,controller/processor 280 of UE 120, and/or any other component(s) ofFIG. 2 may perform one or more techniques associated with spatialdiversity in a coordinated multipoint network, as described in moredetail elsewhere herein. For example, controller/processor 240 of basestation 110, controller/processor 280 of UE 120, and/or any othercomponent(s) of FIG. 2 may perform or direct operations of, for example,process 900 of FIG. 9, process 1000 of FIG. 10, and/or other processesas described herein. Memories 242 and 282 may store data and programcodes for base station 110 and UE 120, respectively. A scheduler 246 mayschedule UEs for data transmission on the downlink and/or uplink.

In some aspects, UE 120 may include means for receiving a plurality ofcommunications from a corresponding plurality of transmission/receptionpoints (TRPs) included in a coordinated multipoint network, wherein atleast two communications, of the plurality of communications, havedifferent redundancy versions from a common codebook and are received ina same transmission time interval (TTI); means for decoding theplurality of communications using joint decoding; and/or the like. Insome aspects, such means may include one or more components of UE 120described in connection with FIG. 2.

In some aspects, base station 110 and/or a TRP associated with basestation 110 may include means for identifying a first redundancy versionfor a first communication to be transmitted to a user equipment (UE) ina transmission time interval (TTI); means for transmitting the firstcommunication, having the first redundancy version, in the TTI, whereinthe first redundancy version is different from a second redundancyversion of a second communication to be transmitted by a second TRP inthe TTI, wherein the second TRP is included in the coordinatedmultipoint network; and/or the like. In some aspects, such means mayinclude one or more components of base station 110 described inconnection with FIG. 2.

As indicated above, FIG. 2 is provided merely as an example. Otherexamples are possible and may differ from what was described with regardto FIG. 2.

FIG. 3A shows an example frame structure 300 for FDD in atelecommunications system (e.g., NR). The transmission timeline for eachof the downlink and uplink may be partitioned into units of radioframes. Each radio frame may have a predetermined duration and may bepartitions into a set of Z (Z≥1) subframes (e.g., with indices of 0through Z−1). Each subframe may include a set of slots (e.g., two slotsper subframe are shown in FIG. 3A). Each slot may include a set of Lsymbol periods (e.g., where L depends on a configuration, whether theslot is a mini-slot, and/or the like). For example, each slot mayinclude seven symbol periods (e.g., as shown in FIG. 3A, such as for atype of mini-slot), fifteen symbol periods, and/or the like. In a casewhere the subframe includes two slots, the subframe may include 2Lsymbol periods, where the 2L symbol periods in each subframe may beassigned indices of 0 through 2L−1. In some aspects, a scheduling unitfor the FDD may frame-based, subframe-based, slot-based, symbol-based(e.g., a number of symbols included in a mini-slot used for scheduling),and/or the like.

While some techniques are described herein in connection with frames,subframes, slots, and/or the like, these techniques may equally apply toother types of wireless communication structures, which may be referredto using terms other than “frame,” “subframe,” “slot,” and/or the likein 5G NR. In some aspects, a wireless communication structure may referto a periodic time-bounded communication unit defined by a wirelesscommunication standard and/or protocol. Additionally, or alternatively,different configurations of wireless communication structures than thoseshown in FIG. 3A may be used.

In certain telecommunications (e.g., NR), a base station may transmitsynchronization signals. For example, a base station may transmit aprimary synchronization signal (PSS), a secondary synchronization signal(SSS), and/or the like, on the downlink for each cell supported by thebase station. The PSS and SSS may be used by UEs for cell search andacquisition. For example, the PSS may be used by UEs to determine symboltiming, and the SSS may be used by UEs to determine a physical cellidentifier, associated with the base station, and frame timing. The basestation may also transmit a physical broadcast channel (PBCH). The PBCHmay carry some system information, such as system information thatsupports initial access by UEs.

In some aspects, the base station may transmit the PSS, the SSS, and/orthe PBCH in accordance with a synchronization communication hierarchy(e.g., a synchronization signal (SS) hierarchy) including multiplesynchronization communications (e.g., SS blocks), as described below inconnection with FIG. 3B.

FIG. 3B is a block diagram conceptually illustrating an example SShierarchy, which is an example of a synchronization communicationhierarchy. As shown in FIG. 3B, the SS hierarchy may include an SS burstset, which may include a plurality of SS bursts (identified as SS burst0 through SS burst B−1, where B is a maximum number of repetitions ofthe SS burst that may be transmitted by the base station). As furthershown, each SS burst may include one or more SS blocks (identified as SSblock 0 through SS block (b_(max) _(_) _(SS−1)), where b_(max) _(_)_(SS−1) is a maximum number of SS blocks that can be carried by an SSburst). In some aspects, different SS blocks may be beam-formeddifferently. An SS burst set may be periodically transmitted by awireless node, such as every X milliseconds, as shown in FIG. 3B. Insome aspects, an SS burst set may have a fixed or dynamic length, shownas Y milliseconds in FIG. 3B.

The SS burst set shown in FIG. 3B is an example of a synchronizationcommunication set, and other synchronization communication sets may beused in connection with the techniques described herein. Furthermore,the SS block shown in FIG. 3B is an example of a synchronizationcommunication, and other synchronization communications may be used inconnection with the techniques described herein.

In some aspects, an SS block includes resources that carry the PSS, theSSS, the PBCH, and/or other synchronization signals (e.g., a tertiarysynchronization signal (TSS)) and/or synchronization channels. In someaspects, multiple SS blocks are included in an SS burst, and the PSS,the SSS, and/or the PBCH may be the same across each SS block of the SSburst. In some aspects, a single SS block may be included in an SSburst. In some aspects, the SS block may be at least four symbol periodsin length, where each symbol carries one or more of the PSS (e.g.,occupying one symbol), the SSS (e.g., occupying one symbol), and/or thePBCH (e.g., occupying two symbols).

In some aspects, the symbols of an SS block are consecutive, as shown inFIG. 3B. In some aspects, the symbols of an SS block arenon-consecutive. Similarly, in some aspects, one or more SS blocks ofthe SS burst may be transmitted in consecutive radio resources (e.g.,consecutive symbol periods) during one or more subframes. Additionally,or alternatively, one or more SS blocks of the SS burst may betransmitted in non-consecutive radio resources.

In some aspects, the SS bursts may have a burst period, whereby the SSblocks of the SS burst are transmitted by the base station according tothe burst period. In other words, the SS blocks may be repeated duringeach SS burst. In some aspects, the SS burst set may have a burst setperiodicity, whereby the SS bursts of the SS burst set are transmittedby the base station according to the fixed burst set periodicity. Inother words, the SS bursts may be repeated during each SS burst set.

The base station may transmit system information, such as systeminformation blocks (SIBs) on a physical downlink shared channel (PDSCH)in certain subframes. The base station may transmit controlinformation/data on a physical downlink control channel (PDCCH) in Csymbol periods of a subframe, where B may be configurable for eachsubframe. The base station may transmit traffic data and/or other dataon the PDSCH in the remaining symbol periods of each subframe.

As indicated above, FIGS. 3A and 3B are provided as examples. Otherexamples are possible and may differ from what was described with regardto FIGS. 3A and 3B.

FIG. 4 shows an example subframe format 410 with a normal cyclic prefix.The available time frequency resources may be partitioned into resourceblocks. Each resource block may cover a set to of subcarriers (e.g., 12subcarriers) in one slot and may include a number of resource elements.Each resource element may cover one subcarrier in one symbol period(e.g., in time) and may be used to send one modulation symbol, which maybe a real or complex value. In some aspects, subframe format 410 may beused for transmission of SS blocks that carry the PSS, the SSS, thePBCH, and/or the like, as described herein.

An interlace structure may be used for each of the downlink and uplinkfor FDD in certain telecommunications systems (e.g., NR). For example, Qinterlaces with indices of 0 through Q−1 may be defined, where Q may beequal to 4, 6, 8, 10, or some other value. Each interlace may includesubframes that are spaced apart by Q frames. In particular, interlace qmay include subframes q, q+Q, q+2Q, etc., where qε{0, . . . , Q−1}.

A UE may be located within the coverage of multiple BSs. One of theseBSs may be selected to serve the UE. The serving BS may be selectedbased at least in part on various criteria such as received signalstrength, received signal quality, path loss, and/or the like. Receivedsignal quality may be quantified by a signal-to-noise-and-interferenceratio (SINR), or a reference signal received quality (RSRQ), or someother metric. The UE may operate in a dominant interference scenario inwhich the UE may observe high interference from one or more interferingBSs.

While aspects of the examples described herein may be associated with NRor 5G technologies, aspects of the present disclosure may be applicablewith other wireless communication systems. New radio (NR) may refer toradios configured to operate according to a new air interface (e.g.,other than Orthogonal Frequency Divisional Multiple Access (OFDMA)-basedair interfaces) or fixed transport layer (e.g., other than InternetProtocol (IP)). In aspects, NR may utilize OFDM with a CP (hereinreferred to as cyclic prefix OFDM or CP-OFDM) and/or SC-FDM on theuplink, may utilize CP-OFDM on the downlink and include support forhalf-duplex operation using TDD. In aspects, NR may, for example,utilize OFDM with a CP (herein referred to as CP-OFDM) and/or discreteFourier transform spread orthogonal frequency-division multiplexing(DFT-s-OFDM) on the uplink, may utilize CP-OFDM on the downlink andinclude support for half-duplex operation using TDD. NR may includeEnhanced Mobile Broadband (eMBB) service targeting wide bandwidth (e.g.,80 megahertz (MHz) and beyond), millimeter wave (mmW) targeting highcarrier frequency (e.g., 60 gigahertz (GHz)), massive MTC (mMTC)targeting non-backward compatible MTC techniques, and/or missioncritical targeting ultra-reliable low latency communications (URLLC)service.

In some aspects, a single component carrier bandwidth of 100 MHZ may besupported. NR resource blocks may span 12 sub-carriers with asub-carrier bandwidth of 60 or 120 kilohertz (kHz) over a 0.1millisecond (ms) duration. Each radio frame may include 40 subframeswith a length of 10 ms. Consequently, each subframe may have a length of0.25 ms. Each subframe may indicate a link direction (e.g., DL or UL)for data transmission and the link direction for each subframe may bedynamically switched. Each subframe may include DL/UL data as well asDL/UL control data.

Beamforming may be supported and beam direction may be dynamicallyconfigured. MIMO transmissions with precoding may also be supported.MIMO configurations in the DL may support up to 8 transmit antennas withmulti-layer DL transmissions up to 8 streams and up to 2 streams per UE.Multi-layer transmissions with up to 2 streams per UE may be supported.Aggregation of multiple cells may be supported with up to 8 servingcells. Alternatively, NR may support a different air interface, otherthan an OFDM-based interface. NR networks may include entities suchcentral units or distributed units.

As indicated above, FIG. 4 is provided as an example. Other examples arepossible and may differ from what was described with regard to FIG. 4.

FIG. 5 illustrates an example logical architecture of a distributed RAN500, according to aspects of the present disclosure. A 5G access node506 may include an access node controller (ANC) 502. The ANC may be acentral unit (CU) of the distributed RAN 500. The backhaul interface tothe next generation core network (NG-CN) 504 may terminate at the ANC.The backhaul interface to neighboring next generation access nodes(NG-ANs) may terminate at the ANC. The ANC may include one or more TRPs508 (which may also be referred to as BSs, NR BSs, Node Bs, 5G NBs, APs,gNB, or some other term). As described above, a TRP may be usedinterchangeably with “cell.”

The TRPs 508 may be a distributed unit (DU). The TRPs may be connectedto one ANC (ANC 502) or more than one ANC (not illustrated). Forexample, for RAN sharing, radio as a service (RaaS), and servicespecific AND deployments, the TRP may be connected to more than one ANC.A TRP may include one or more antenna ports. The TRPs may be configuredto individually (e.g., dynamic selection) or jointly (e.g., jointtransmission) serve traffic to a UE.

The local architecture of RAN 500 may be used to illustrate fronthauldefinition. The architecture may be defined that support fronthaulingsolutions across different deployment types. For example, thearchitecture may be based at least in part on transmit networkcapabilities (e.g., bandwidth, latency, and/or jitter).

The architecture may share features and/or components with LTE.According to aspects, the next generation AN (NG-AN) 510 may supportdual connectivity with NR. The NG-AN may share a common fronthaul forLTE and NR.

The architecture may enable cooperation between and among TRPs 508. Forexample, cooperation may be preset within a TRP and/or across TRPs viathe ANC 502. According to aspects, no inter-TRP interface may beneeded/present.

According to aspects, a dynamic configuration of split logical functionsmay be present within the architecture of RAN 500. The packet dataconvergence protocol (PDCP), radio link control (RLC), media accesscontrol (MAC) protocol may be adaptably placed at the ANC or TRP.

According to various aspects, a BS may include a central unit (CU)(e.g., ANC 502) and/or one or more distributed units (e.g., one or moreTRPs 508).

As indicated above, FIG. 5 is provided merely as an example. Otherexamples are possible and may differ from what was described with regardto FIG. 5.

FIG. 6 illustrates an example physical architecture of a distributed RAN600, according to aspects of the present disclosure. A centralized corenetwork unit (C-CU) 602 may host core network functions. The C-CU may becentrally deployed. C-CU functionality may be offloaded (e.g., toadvanced wireless services (AWS)), in an effort to handle peak capacity.

A centralized RAN unit (C-RU) 604 may host one or more ANC functions.Optionally, the C-RU may host core network functions locally. The C-RUmay have distributed deployment. The C-RU may be closer to the networkedge.

A distributed unit (DU) 606 may host one or more TRPs. The DU may belocated at edges of the network with radio frequency (RF) functionality.

As indicated above, FIG. 6 is provided merely as an example. Otherexamples are possible and may differ from what was described with regardto FIG. 6.

FIG. 7 is a diagram illustrating an example 700 of spatial diversity ina coordinated multipoint network, in accordance with various aspects ofthe present disclosure.

As shown in FIG. 7, a UE 120 (e.g., an MTC UE and/or the like, shown asa robotic arm) may be capable of communicating with multiple TRPs 705(e.g., a base station 110, an antenna 234 of base station 110, a TRP508, a DU 606, and/or the like), shown as a first TRP 705-1 and a secondTRP 705-2. The multiple TRPs 705 may be included in a coordinatedmultipoint network 710, and transmissions of the TRPs 705 may becoordinated (e.g., controlled, scheduled, generated) using a controller715 (e.g., a network controller 130, a controller/processor 240 of basestation 110, an ANC 502, a C-RU 604, and/or the like) that exchangesinformation with the TRPs 705. The coordinated multipoint network 710may be used to send information to the UE 120 and/or receive informationfrom the UE 120 via multiple TRPs 705 to improve performance (e.g., incase of dynamic network conditions, poor network conditions, and/or thelike).

In some aspects, the controller 715 may be a base station (e.g., thatincludes a controller/processor 240, a memory 242, a scheduler 246,and/or the like of base station 110), and the TRPs 705 may be remoteradio heads of the base station (e.g., which may includetransmit/receive components of base station 110, such as transmitprocessor 220, TX MIMO processor 230, MOD/DEMOD 232, antenna 234, MIMOdetector 236, receive processor 238, and/or the like). In some aspects,the controller 715 may be a network controller (e.g., network controller130), and the TRPs 705 may be base stations 110 in communication withthe network controller.

In some aspects, at least two TRPs 705 in the coordinated multipointnetwork 710 (e.g., the first TRP 705-1 and the second TRP 705-2) may usedifferent frequency bands for communication. For example, thecoordinated multipoint network 710 may be a frequency reuse network(e.g., may employ frequency reuse across TRPs 705), where different TRPs705 reuse frequency bands, but adjacent TRPs 705 use different frequencybands to mitigate interference. In this case, the first TRP 705-1 andthe second TRP 705-2 may be adjacent TRPs 705 or may otherwise usedifferent frequency bands for communication (e.g., according to afrequency reuse pattern employed by the coordinated multipoint network710). Although the coordinated multipoint network 710 of FIG. 7 showstwo TRPs 705, in practice, the coordinated multipoint network 710 mayinclude more than two TRPs 705.

The TRPs 705 in the coordinated multipoint network 710 may usecoordinated scheduling and/or coordinated beamforming to improveperformance. In coordinated scheduling, the TRPs 705 may communicatewith the controller 715, which may perform centralized scheduling fortransmissions to a UE 120 (or multiple UEs 120) by multiple TRPs 705.The transmissions may be scheduled to occur at the same time (e.g.,using the same frequency or different frequencies), or may be scheduledto occur at different times (e.g., using the same frequency or differentfrequencies), so as to improve reception by the UE 120. In some aspects,multiple TRPs 705 may share channel state information for communicatingwith UEs 120, but a data packet to be transmitted to a UE 120 may beavailable only at a single TRP 705. In some aspects, the TRPs 705 andthe controller 715 may communicate using a local time sensitive networkto reduce the latency of information exchanged between a TRP 705 and thecontroller 715. The local time sensitive network may be a wired network,a wireless network, or a network that includes both wired communicationand wireless communication.

In some aspects, the controller 715 may instruct the TRPs 705 totransmit using joint transmission (JT), where multiple TRPs 705 transmitthe same information to a UE 120 in the same time slot using coordinatedbeamforming (e.g., with appropriate beamforming weights applied totransmissions by different TRPs 705). In some aspects, the controller715 may instruct the TRPs 705 to transmit using dynamic point selection(DPS), where a single TRP 705 transmits information to a UE 120 per timeslot (e.g., using appropriate beamforming, which may be indicated to theTRP 705 by the controller 715), and where different TRPs 705 may bescheduled for transmission to the UE 120 in different time slots. Thismay improve performance by dynamically scheduling different TRPs 705 totransmit information to the UE 120 based at least in part on channelconditions, which may account for shadowing, channel fading, and/or thelike.

However, in some settings, such as an industrial environment (e.g., afactory that uses factory automation for communication betweenmachines), a channel condition referred to as fast shadowing may occur.In fast shadowing, channel conditions may change very quickly due toreflection and/or blockage of signals by machines that move rapidly(e.g., a mechanical arm, a robot, and/or the like), such as up to 20meters per second, for example. Often, channel conditions in fastshadowing may change so rapidly (e.g., every 10ms and/or the like) thatre-association and/or handover to a different TRP 705, which may takeapproximately 65-90 ms, may not be fast enough to keep up with thechange in channel conditions (e.g., channel conditions may changedramatically before handover is completed). In this case, transmissionsby multiple TRPs 705 in a coordinated multipoint network 710 may be usedto increase spatial diversity and improve reception of signals.

In some aspects, a hybrid automatic repeat request (HARQ) procedure maybe used in a coordinated multipoint network 710 and/or in a settingwhere fast shadowing may occur. In this case, channel conditions maychange rapidly, such that the TRP 705 that transmits a failedcommunication to a UE 120 (e.g., a communication for which the UE 120responds with a negative acknowledgement, or NACK) may have poor channelconditions with the UE 120 after the NACK is received and aretransmission is to occur. In this case, one or more retransmissionsmay be transmitted by a different TRP 705 and/or by multiple TRPs 705(e.g., including or excluding the original TRP 705 that transmitted thefailed communication).

Some techniques and apparatuses described herein permit the use ofspatial diversity in a coordinated multipoint network, thereby improvingnetwork performance and permitting the TRPs 705 to communicate with theUE 120 in a low latency, high reliability network, such as a URLLCnetwork (e.g., to satisfy a latency requirement, a reliabilityrequirement, a URLLC requirement, and/or the like). For example, sometechniques and apparatuses described herein may permit satisfaction ofone or more network requirements associated with a factory automationsetting, such as a latency requirement (e.g., of 1 ms, 5 ms, 10 ms,and/or the like), a reliability requirement (e.g., of 10⁻⁵, 10⁻⁷, 10⁻⁹,and/or the like), and/or the like. Furthermore, some techniques andapparatuses described herein use joint decoding (e.g., with incrementalredundancy) to improve decoding performance for communications receivedfrom multiple TRPs 705 using spatial diversity.

As shown by reference number 720, the UE 120 may receive multiplecommunications from corresponding multiple TRPs 705 included in thecoordinated multipoint network 710, and different communications of themultiple communications may have different redundancy versions. Forexample, the UE 120 may receive a first communication from the first TRP705-1, and may receive a second communication from the second TRP 705-1.The first communication and the second communication may be differentredundancy versions of a common communication (e.g., the samecommunication). The different redundancy versions may be derived from acommon codebook, where the same codeword is punctured differently togenerate different redundancy versions that include differentcombinations of information bits and parity bits.

In some aspects, the common communication may be an initialcommunication (e.g., other than a HARQ retransmission). In this case,the first communication and the second communication may be differentredundancy versions of the initial communication. In some aspects, thecommon communication may be a retransmission (e.g., a HARQretransmission), as described in more detail below in connection withFIG. 8. In this case, the first communication and the secondcommunication may be different redundancy versions of theretransmission.

In example 700, the UE 120 is shown as receiving a first communication,having a first redundancy version, from the first TRP 705-1 andreceiving a second communication, having a second redundancy version,from the second TRP 705-2. In this case, the first TRP 705-1 mayidentify the first redundancy version (e.g., based at least in part oninformation received from the controller 715 and/or hard-coded in memoryof the first TRP 705-1), and may transmit the first communication,having the first redundancy version, to the UE 120. Similarly, thesecond TRP 705-2 may identify the second redundancy version, and maytransmit the second communication, having the second redundancy version,to the UE 120. In practice, the UE 120 may receive a different number ofcommunications (e.g., three communications, four communications, and/orthe like) from a different number of TRPs 705 (e.g., three TRPs 705,four TRPs 705, and/or the like). In some aspects, all of the receivedcommunications may have different redundancy versions. In some aspects,fewer than all of the received communications may have differentredundancy versions.

As shown by reference number 725, the multiple communications may betransmitted and/or received in a same transmission time interval (TTI),such as a subframe, a slot, a mini-slot, a number of symbols, and/or thelike. In some aspects, the TTI is a self-contained TTI, where downlinkcontrol information (DCI) (e.g., a downlink grant and/or the like),downlink data corresponding to the DCI, and uplink control information(UCI) (e.g., acknowledgement (ACK) or negative acknowledgment (NACK)feedback and/or the like) corresponding to the downlink data are allcommunicated within the TTI.

For example, one or more TRPs 705 may transmit, and the UE 120 mayreceive, DCI in a downlink control channel portion 730 (e.g., shown asPDCCH) of the TTI. The DCI may include control information regarding afirst communication 735, from the first TRP 705-1 (e.g., shown as TRP1), and a second communication 740 from the second TRP 705-2 (e.g.,shown as TRP 2). For example, the DCI may indicate a first set ofresource blocks (e.g., time and/or frequency resources) to be monitoredby the UE 120 to receive the first communication 735, and may indicate asecond set of resource blocks to be monitored by the UE 120 to receivethe second communication 740. As shown, the first communication may havea first redundancy version (e.g., shown as RV 1), and the secondcommunication may have a second redundancy version (e.g., shown as RV2). In some aspects, the redundancy versions of the communications 735,740 may be indicated in the DCI.

As shown by reference number 745, the UE 120 may decode the multiplecommunications using joint decoding. For example, because the multiplecommunications have different redundancy versions, the UE 120 may useincremental redundancy (e.g., instead of chase combining) to decode thecommunications, thereby increasing a decoding speed, increasing adecoding accuracy, reducing network resources needed forretransmissions, and/or the like. In this way, spatial diversity may beused within the coordinated multipoint network 710 to improve decodingperformance and improve network performance (e.g., to satisfy a latencyrequirement, a reliability requirement, a URLLC requirement, and/or thelike).

As shown by reference number 750, in some aspects, the UE 120 maytransmit, and one or more TRPs 705 may receive, UCI in the TTI. In someaspects, the UCI may include ACK or NACK feedback for the firstcommunication and/or the second communication. In some aspects, if theUE 120 is unable to decode the common communication using the firstcommunication and the second communication, the UE 120 may transmit aNACK, and may receive multiple retransmissions, from multiple TRPs 705,that are different redundancy versions of the common communication, asdescribed below in connection with FIG. 8.

As indicated above, FIG. 7 is provided as an example. Other examples arepossible and may differ from what was described with respect to FIG. 7.

FIG. 8 is a diagram illustrating another example 800 of spatialdiversity in a coordinated multipoint network, in accordance withvarious aspects of the present disclosure.

As shown by reference number 805, a communication from a TRP 705 to theUE 120 may fail, and the UE 120 may determine that the communication hasfailed (e.g., was not successfully received). For example, the UE 120may receive the communication (e.g., a packet and/or the like), and maybe unable to decode the communication, may detect an error afterdecoding the communication (e.g., after performing a cyclic redundancycheck), and/or the like. In some aspects, the communication may be aninitial communication (e.g., not a retransmission). In some aspects, thecommunication may be a retransmission.

As shown by reference number 810, the UE 120 may transmit a negativeacknowledgement (NACK) corresponding to the failed communication basedat least in part on determining that the communication was notsuccessfully received. As shown, in some aspects, the UE 120 maytransmit the NACK to the same TRP 705 that transmitted the failedcommunication. However, in some aspects, the UE 120 may transmit theNACK to a TRP 705 other than the TRP 705 that transmitted the failedcommunication (e.g., the UE 120 may transmit the NACK to a plurality ofTRPs 705 that include the TRP 705 that transmitted the failedcommunication, the UE 120 may transmit the NACK to one or more TRPs 705that do not include the TRP 705 that transmitted the failedcommunication, and/or the like).

As shown by reference number 815, the failed communication and/or theNACK may be transmitted and/or received in the same TTI (e.g., aself-contained TTI), such as a subframe, a slot, a mini-slot, a numberof symbols, and/or the like. For example, the failed communication maybe transmitted and/or received in a data portion (e.g., shown as PDSCH)of the TTI, and the NACK may be transmitted in an uplink control portion(e.g., shown as UCI) of the TTI.

As shown by reference number 820, based at least in part on receivingthe NACK, multiple TRPs 705 in the coordinated multipoint network 710may transmit retransmissions that are different redundancy versions of acommon retransmission (e.g., the same retransmission), in a similarmanner as described above in connection with FIG. 7. For example, one ormore TRPs 705 may receive the NACK, and may report the NACK to thecontroller 715, which may coordinate the retransmissions by multipleTRPs 705. As shown, the UE 120 may receive the multiple retransmissionsfrom corresponding multiple TRPs 705 based at least in part ontransmitting the NACK corresponding to the failed communication. Forexample, the UE 120 may receive a first retransmission from the firstTRP 705-1, and may receive a second retransmission from the second TRP705-1. The first retransmission and the second retransmission may bedifferent redundancy versions of a common communication (e.g., the sameretransmission), as described above in connection with FIG. 7. In someaspects, the TRP 705 that transmitted the failed communication (e.g.,the first TRP 705-1) may transmit a retransmission to the UE 120, andthe UE 120 may receive such a communication, as shown. However, in someaspects, the TRP 705 that transmitted the failed communication may nottransmit a retransmission to the UE 120, and multiple TRPs 705 otherthan that TRP 705 may transmit the retransmissions to the UE 120.

As shown by reference number 825, the multiple retransmissions may betransmitted and/or received in a same transmission time interval (TTI)(e.g., a self-contained TTI), such as a subframe, a slot, a mini-slot, anumber of symbols, and/or the like. For example, one or more TRPs 705may transmit, and the UE 120 may receive, DCI in a downlink controlchannel portion 830 (e.g., shown as PDCCH) of the TTI. The DCI mayinclude control information regarding a first retransmission 835, fromthe first TRP 705-1 (e.g., shown as TRP 1), and a second retransmission840 from the second TRP 705-2 (e.g., shown as TRP 2), as described abovein connection with FIG. 7. As shown, the first retransmission may have afirst redundancy version (e.g., shown as RV 1), and the secondretransmission may have a second redundancy version (e.g., shown as RV2). In some aspects, the TTI that includes the retransmission mayimmediately follow the TTI that includes the failed communication, so asto reduce latency.

As shown by reference number 845, the UE 120 may decode the multipleretransmissions using joint decoding (e.g., incremental redundancy), ina similar manner as described above in connection with FIG. 7, therebyincreasing a decoding speed, increasing a decoding accuracy, reducingnetwork resources needed for retransmissions, and/or the like. In thisway, spatial diversity may be used within the coordinated multipointnetwork 710 to improve decoding performance and improve networkperformance (e.g., to satisfy a latency requirement, a reliabilityrequirement, a URLLC requirement, and/or the like).

As shown by reference number 850, in some aspects, the UE 120 maytransmit, and one or more TRPs 705 may receive, UCI in the TTI thatincludes the retransmissions. In some aspects, the UCI may include ACKor NACK feedback for the first retransmission and/or the secondretransmission. In some aspects, if the UE 120 is unable to decode thecommon retransmission using the first retransmission and the secondretransmission, the UE 120 may transmit one or more NACKs, and mayreceive multiple retransmissions, from multiple TRPs 705, that aredifferent redundancy versions of the common retransmission, in a similarmanner as described above.

As indicated above, FIG. 8 is provided as an example. Other examples arepossible and may differ from what was described with respect to FIG. 8.

FIG. 9 is a diagram illustrating an example process 900 performed, forexample, by a UE, in accordance with various aspects of the presentdisclosure. Example process 900 is an example where a UE (e.g., UE 120and/or the like) performs operations to assist with achieving spatialdiversity in a coordinated multipoint network.

As shown in FIG. 9, in some aspects, process 900 may include receiving aplurality of communications from a corresponding plurality oftransmission/reception points (TRPs) included in a coordinatedmultipoint network, wherein at least two communications, of theplurality of communications, have different redundancy versions from acommon codebook and are received in a same transmission time interval(TTI) (block 910). For example, the UE may receive (e.g., using antenna252, DEMOD 254, MIMO detector 256, receive processor 258,controller/processor 280, and/or the like) a plurality of communicationsfrom a corresponding plurality of TRPs included in a coordinatedmultipoint network, as described above in connection with FIGS. 7 and 8.In some aspects, at least two communications, of the plurality ofcommunications, have different redundancy versions from a commoncodebook. In some aspects, the at least two communications are receivedin a same TTI.

As further shown in FIG. 9, in some aspects, process 900 may includedecoding the plurality of communications using joint decoding (block920). For example, the UE may decode (e.g., using MIMO detector 256,receive processor 258, controller/processor 280 and/or the like) theplurality of communications using joint decoding, as described above inconnection with FIGS. 7 and 8.

Process 900 may include additional aspects, such as any single aspect orany combination of aspects described below.

In some aspects, the plurality of communications are differentredundancy versions of an initial transmission. In some aspects, theplurality of communications are different redundancy versions of aretransmission.

In some aspects, the plurality of communications are received based atleast in part on transmitting a negative acknowledgement (NACK)corresponding to a failed communication from a TRP included in thecoordinated multipoint network. In some aspects, a communication, of theplurality of communications, is received from the TRP. In some aspects,the plurality of communications are received from TRPs other than theTRP.

In some aspects, the plurality of TRPs include a plurality of remoteradio heads of a same base station. In some aspects, the plurality ofTRPs include a plurality of base stations in communication with acontroller. In some aspects, the TTI is a slot, a mini-slot, or a numberof symbols. In some aspects, the plurality of TRPs communicate with theUE in a low latency, high reliability network.

Although FIG. 9 shows example blocks of process 900, in some aspects,process 900 may include additional blocks, fewer blocks, differentblocks, or differently arranged blocks than those depicted in FIG. 9.Additionally, or alternatively, two or more of the blocks of process 900may be performed in parallel.

FIG. 10 is a diagram illustrating an example process 1000 performed, forexample, by a TRP, in accordance with various aspects of the presentdisclosure. Example process 1000 is an example where a TRP (e.g., basestation 110, TRP 705, and/or the like) performs operations to assistwith achieving spatial diversity in a coordinated multipoint network.

As shown in FIG. 10, in some aspects, process 1000 may includeidentifying a first redundancy version for a first communication to betransmitted to a user equipment (UE) in a transmission time interval(TTI) (block 1010). For example, a first TRP may identify (e.g., usingcontroller/processor 240, input from communication unit 244, input fromdata source 212, and/or the like) a first redundancy version for a firstcommunication to be transmitted to a UE in a TTI, as described above inconnection with FIGS. 7 and 8.

As further shown in FIG. 10, in some aspects, process 1000 may includetransmitting the first communication, having the first redundancyversion, in the TTI, wherein the first redundancy version is differentfrom a second redundancy version of a second communication to betransmitted by a second TRP in the TTI, wherein the second TRP isincluded in a coordinated multipoint network (block 1020). For example,the first TRP may transmit (e.g., using controller/processor 240,transmit processor 220, TX MIMO processor 230, MOD 232, antenna 234,and/or the like) the first communication, having the first redundancyversion, in the TTI, as described above in connection with FIGS. 7 and8. In some aspects, the first redundancy version is different from asecond redundancy version of a second communication to be transmitted bya second TRP in the TTI. In some aspects, the second TRP is included ina coordinated multipoint network with the first TRP.

Process 1000 may include additional aspects, such as any single aspector any combination of aspects described below.

In some aspects, the first communication and the second communicationare different redundancy versions of an initial transmission. In someaspects, the first communication and the second communication aredifferent redundancy versions of a retransmission.

In some aspects, the first communication and the second communicationare transmitted based at least in part on receiving a negativeacknowledgement (NACK) corresponding to a failed communication from aTRP included in the coordinated multipoint network. In some aspects, theTRP is the first TRP. In some aspects, the TRP is not the first TRP.

In some aspects, the first TRP and the second TRP are different remoteradio heads of a same base station. In some aspects, the first TRP andthe second TRP are different base stations in communication with acontroller. In some aspects, the TTI is a slot, a mini-slot, or a numberof symbols. In some aspects, the first TRP and the second TRPcommunicate with the UE in a low latency, high reliability network.

Although FIG. 10 shows example blocks of process 1000, in some aspects,process 1000 may include additional blocks, fewer blocks, differentblocks, or differently arranged blocks than those depicted in FIG. 10.Additionally, or alternatively, two or more of the blocks of process1000 may be performed in parallel.

The foregoing disclosure provides illustration and description, but isnot intended to be exhaustive or to limit the aspects to the preciseform disclosed. Modifications and variations are possible in light ofthe above disclosure or may be acquired from practice of the aspects.

As used herein, the term component is intended to be broadly construedas hardware, firmware, or a combination of hardware and software. Asused herein, a processor is implemented in hardware, firmware, or acombination of hardware and software.

Some aspects are described herein in connection with thresholds. As usedherein, satisfying a threshold may refer to a value being greater thanthe threshold, greater than or equal to the threshold, less than thethreshold, less than or equal to the threshold, equal to the threshold,not equal to the threshold, and/or the like.

It will be apparent that systems and/or methods, described herein, maybe implemented in different forms of hardware, firmware, or acombination of hardware and software. The actual specialized controlhardware or software code used to implement these systems and/or methodsis not limiting of the aspects. Thus, the operation and behavior of thesystems and/or methods were described herein without reference tospecific software code—it being understood that software and hardwarecan be designed to implement the systems and/or methods based, at leastin part, on the description herein.

Even though particular combinations of features are recited in theclaims and/or disclosed in the specification, these combinations are notintended to limit the disclosure of possible aspects. In fact, many ofthese features may be combined in ways not specifically recited in theclaims and/or disclosed in the specification. Although each dependentclaim listed below may directly depend on only one claim, the disclosureof possible aspects includes each dependent claim in combination withevery other claim in the claim set. A phrase referring to “at least oneof” a list of items refers to any combination of those items, includingsingle members. As an example, “at least one of: a, b, or c” is intendedto cover a, b, c, a-b, a-c, b-c, and a-b-c, as well as any combinationwith multiples of the same element (e.g., a-a, a-a-a, a-a-b, a-a-c,a-b-b, a-c-c, b-b, b-b-b, b-b-c, c-c, and c-c-c or any other ordering ofa, b, and c).

No element, act, or instruction used herein should be construed ascritical or essential unless explicitly described as such. Also, as usedherein, the articles “a” and “an” are intended to include one or moreitems, and may be used interchangeably with “one or more.” Furthermore,as used herein, the terms “set” and “group” are intended to include oneor more items (e.g., related items, unrelated items, a combination ofrelated and unrelated items, and/or the like), and may be usedinterchangeably with “one or more.” Where only one item is intended, theterm “one” or similar language is used. Also, as used herein, the terms“has,” “have,” “having,” and/or the like are intended to be open-endedterms. Further, the phrase “based on” is intended to mean “based, atleast in part, on” unless explicitly stated otherwise.

What is claimed is:
 1. A method of wireless communication performed by auser equipment (UE), comprising: receiving a plurality of communicationsfrom a corresponding plurality of transmission/reception points (TRPs)included in a coordinated multipoint network, wherein at least twocommunications, of the plurality of communications, have differentredundancy versions from a common codebook and are received in a sametransmission time interval (TTI); and decoding the plurality ofcommunications using joint decoding.
 2. The method of claim 1, whereinthe plurality of communications are different redundancy versions of aninitial transmission.
 3. The method of claim 1, wherein the plurality ofcommunications are different redundancy versions of a retransmission. 4.The method of claim 1, wherein the plurality of communications arereceived based at least in part on transmitting a negativeacknowledgement (NACK) corresponding to a failed communication from aTRP included in the coordinated multipoint network.
 5. The method ofclaim 4, wherein a communication, of the plurality of communications, isreceived from the TRP.
 6. The method of claim 4, wherein the pluralityof communications are received from TRPs other than the TRP.
 7. Themethod of claim 1, wherein the plurality of TRPs include a plurality ofremote radio heads of a same base station.
 8. The method of claim 1,wherein the plurality of TRPs include a plurality of base stations incommunication with a controller.
 9. The method of claim 1, wherein theTTI is a slot, a mini-slot, or a number of symbols.
 10. The method ofclaim 1, wherein the plurality of TRPs communicate with the UE in a lowlatency, high reliability network.
 11. A method of wirelesscommunication performed by a first transmission/reception point (TRP)included in a coordinated multipoint network, comprising: identifying afirst redundancy version for a first communication to be transmitted toa user equipment (UE) in a transmission time interval (TTI); andtransmitting the first communication, having the first redundancyversion, in the TTI, wherein the first redundancy version is differentfrom a second redundancy version of a second communication to betransmitted by a second TRP in the TTI, wherein the second TRP isincluded in the coordinated multipoint network.
 12. The method of claim11, wherein the first communication and the second communication aredifferent redundancy versions of an initial transmission.
 13. The methodof claim 11, wherein the first communication and the secondcommunication are different redundancy versions of a retransmission. 14.The method of claim 11, wherein the first communication and the secondcommunication are transmitted based at least in part on receiving anegative acknowledgement (NACK) corresponding to a failed communicationfrom a TRP included in the coordinated multipoint network.
 15. Themethod of claim 14, wherein the TRP is the first TRP.
 16. The method ofclaim 14, wherein the TRP is not the first TRP.
 17. The method of claim11, wherein the first TRP and the second TRP are different remote radioheads of a same base station.
 18. The method of claim 11, wherein thefirst TRP and the second TRP are different base stations incommunication with a controller.
 19. The method of claim 11, wherein theTTI is a slot, a mini-slot, or a number of symbols.
 20. The method ofclaim 11, wherein the first TRP and the second TRP communicate with theUE in a low latency, high reliability network.
 21. A user equipment (UE)for wireless communication, comprising: memory; and one or moreprocessors coupled to the memory, the memory and the one or moreprocessors configured to: receive a plurality of communications from acorresponding plurality of transmission/reception points (TRPs) includedin a coordinated multipoint network, wherein at least twocommunications, of the plurality of communications, have differentredundancy versions from a common codebook and are received in a sametransmission time interval (TTI); and decode the plurality ofcommunications using joint decoding.
 22. The UE of claim 21, wherein theplurality of communications are different redundancy versions of aninitial transmission or a retransmission.
 23. The UE of claim 21,wherein the plurality of communications are received based at least inpart on transmitting a negative acknowledgement (NACK) corresponding toa failed communication from a TRP included in the coordinated multipointnetwork.
 24. The UE of claim 23, wherein a communication, of theplurality of communications, is received from the TRP.
 25. The UE ofclaim 23, wherein the plurality of communications are received from TRPsother than the TRP.
 26. A first transmission/reception point (TRP),included in a coordinated multipoint network, for wirelesscommunication, comprising: memory; and one or more processors coupled tothe memory, the memory and the one or more processors configured to:identify a first redundancy version for a first communication to betransmitted to a user equipment (UE) in a transmission time interval(TTI); and transmit the first communication, having the first redundancyversion, in the TTI, wherein the first redundancy version is differentfrom a second redundancy version of a second communication to betransmitted by a second TRP in the TTI, wherein the second TRP isincluded in the coordinated multipoint network.
 27. The first TRP ofclaim 26, wherein the first communication and the second communicationare different redundancy versions of an initial transmission or aretransmission.
 28. The first TRP of claim 26, wherein the firstcommunication and the second communication are transmitted based atleast in part on receiving a negative acknowledgement (NACK)corresponding to a failed communication from a TRP included in thecoordinated multipoint network.
 29. The first TRP of claim 28, whereinthe TRP is the first TRP.
 30. The first TRP of claim 28, wherein the TRPis not the first TRP.